Hot Rolling vs. Investment Casting
What’s the Difference?
Manufacturing metal parts require just as much forethought about the end-use of the product as it does research for your metal fabrication partner. The use of metal parts in projects touches every part of the supply chain; from the product innovator to the CFO who is responsible for ensuring operational efficiency. For large-size parts, project leaders must use a strategic approach to compare cost advantages, lean processes, and quality standards. Choosing the right technique at the beginning of a project is critical to meet budget demands and deliver a quality product.
If you’re in the research phase of a large-parts project, you’re likely comparing forming processes. Hot rolling and investment casting are two popular forming methods for creating steel parts used in equipment, transportation, and construction projects.
Hot Rolling and Investment Casting
Two different forming methods
In investment casting, the metal is heated above its melting point and poured (not injected) into a mold to solidify. Modern investment casting techniques guarantee wear-resistant components and accuracy for complex geometries. Investment casting is a popular choice for parts used in the transportation industry as well as the firearm industry, medical equipment, construction and mechanical tools, and more. The net shape/near-net shape of investment castings offer significant savings in the cost of materials, machining, and labor.
The hot rolling process occurs at temperatures above 1,000 degrees Fahrenheit. Hot rolled steel will reconfigure itself during the cooling down process, which gives the finished product looser tolerances than the original material. These looser tolerances make hot rolled steel a good choice for the manufacturing of structural components, such as I-beams for support trusses or simple cross sections for railway tracks. In the automotive industry, hot rolled steel can be used for truck frames and automobile seat frames. Rolled steel manufacturers also use the hot rolling process to produce sheet metal.
Metal Specifications and Grades
Hot rolled steel will reconfigure itself during the cooling down process, which gives the finished product looser tolerances than the original material (and as compared to investment casting). There is less control over hot rolled steel’s final shape because it’s cooled after processing, which makes it less suitable for precision applications. It’s commonly used for transportation and construction projects where very specific dimensions aren’t critical. Most hot rolling processes involve steel, but aluminum hot rolling is popular for electrical and automation equipment.
Investment casting is much more precise than hot rolling, making it a popular choice for projects that require a high level of accuracy, integrity, and multiple production iterations.
Strength & Application
Both hot rolling and investment casting produce tough, strong parts with reliable quality, and both are used in transportation applications, industrial equipment, tools, and construction. One of the main advantages of investment casting is better for wearable parts that require smooth surfaces and low tolerances. For parts with complex shapes that require dimensional accuracy, investment casting delivers a strong product at a competitive price with lower-than-average tooling costs. Hot rolled steel is used in applications where precise shapes and tolerances aren’t necessary; the final products are often used as solutions for rods, structural sections, and rails.
Size & Cost
While almost any metal can be melted and poured into an investment cast, characteristics vary and the final shape and aspect ratio will determine if the investment is the most economical fabrication process available. An experienced custom stainless steel casting foundry will help you with the prototyping process, giving you the opportunity to evaluate a sample part before placing an order for hundreds or thousands of units. If your project requires metal sheets or thin films, hot rolling is most likely the fabrication process for you, due to size and costs.
At KICastings, we offer custom mold making services with design and prototyping guidance. We have an in-house dedicated mold shop, and we’re committed to delivering quality investment casting services with the best equipment in the business. Use our Request a Quote form to tell us more about your project and we’ll be happy to assist you.